// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

(function(mod) {
    if (typeof exports == "object" && typeof module == "object") // CommonJS
        mod(require("../../lib/codemirror"));
    else if (typeof define == "function" && define.amd) // AMD
        define(["../../lib/codemirror"], mod);
    else // Plain browser env
        mod(CodeMirror);
})(function(CodeMirror) {
    "use strict";

    var HINT_ELEMENT_CLASS        = "CodeMirror-hint";
    var ACTIVE_HINT_ELEMENT_CLASS = "CodeMirror-hint-active";

    // This is the old interface, kept around for now to stay
    // backwards-compatible.
    CodeMirror.showHint = function(cm, getHints, options) {
        if (!getHints) return cm.showHint(options);
        if (options && options.async) getHints.async = true;
        var newOpts = {hint: getHints};
        if (options) for (var prop in options) newOpts[prop] = options[prop];
        return cm.showHint(newOpts);
    };

    CodeMirror.defineExtension("showHint", function(options) {
        options = parseOptions(this, this.getCursor("start"), options);
        var selections = this.listSelections()
        if (selections.length > 1) return;
        // By default, don't allow completion when something is selected.
        // A hint function can have a `supportsSelection` property to
        // indicate that it can handle selections.
        if (this.somethingSelected()) {
            if (!options.hint.supportsSelection) return;
            // Don't try with cross-line selections
            for (var i = 0; i < selections.length; i++)
                if (selections[i].head.line != selections[i].anchor.line) return;
        }

        if (this.state.completionActive) this.state.completionActive.close();
        var completion = this.state.completionActive = new Completion(this, options);
        if (!completion.options.hint) return;

        CodeMirror.signal(this, "startCompletion", this);
        completion.update(true);
    });

    function Completion(cm, options) {
        this.cm = cm;
        this.options = options;
        this.widget = null;
        this.debounce = 0;
        this.tick = 0;
        this.startPos = this.cm.getCursor("start");
        this.startLen = this.cm.getLine(this.startPos.line).length - this.cm.getSelection().length;

        var self = this;
        cm.on("cursorActivity", this.activityFunc = function() { self.cursorActivity(); });
    }

    var requestAnimationFrame = window.requestAnimationFrame || function(fn) {
        return setTimeout(fn, 1000/60);
    };
    var cancelAnimationFrame = window.cancelAnimationFrame || clearTimeout;

    Completion.prototype = {
        close: function() {
            if (!this.active()) return;
            this.cm.state.completionActive = null;
            this.tick = null;
            this.cm.off("cursorActivity", this.activityFunc);

            if (this.widget && this.data) CodeMirror.signal(this.data, "close");
            if (this.widget) this.widget.close();
            CodeMirror.signal(this.cm, "endCompletion", this.cm);
        },

        active: function() {
            return this.cm.state.completionActive == this;
        },

        pick: function(data, i) {
            var completion = data.list[i];
            if (completion.hint) completion.hint(this.cm, data, completion);
            else this.cm.replaceRange(getText(completion), completion.from || data.from,
                completion.to || data.to, "complete");
            CodeMirror.signal(data, "pick", completion);
            this.close();
        },

        cursorActivity: function() {
            if (this.debounce) {
                cancelAnimationFrame(this.debounce);
                this.debounce = 0;
            }

            var pos = this.cm.getCursor(), line = this.cm.getLine(pos.line);
            if (pos.line != this.startPos.line || line.length - pos.ch != this.startLen - this.startPos.ch ||
                pos.ch < this.startPos.ch || this.cm.somethingSelected() ||
                (!pos.ch || this.options.closeCharacters.test(line.charAt(pos.ch - 1)))) {
                this.close();
            } else {
                var self = this;
                this.debounce = requestAnimationFrame(function() {self.update();});
                if (this.widget) this.widget.disable();
            }
        },

        update: function(first) {
            if (this.tick == null) return
            var self = this, myTick = ++this.tick
            fetchHints(this.options.hint, this.cm, this.options, function(data) {
                if (self.tick == myTick) self.finishUpdate(data, first)
            })
        },

        finishUpdate: function(data, first) {
            if (this.data) CodeMirror.signal(this.data, "update");

            var picked = (this.widget && this.widget.picked) || (first && this.options.completeSingle);
            if (this.widget) this.widget.close();

            this.data = data;

            if (data && data.list.length) {
                if (picked && data.list.length == 1) {
                    this.pick(data, 0);
                } else {
                    this.widget = new Widget(this, data);
                    CodeMirror.signal(data, "shown");
                }
            }
        }
    };

    function parseOptions(cm, pos, options) {
        var editor = cm.options.hintOptions;
        var out = {};
        for (var prop in defaultOptions) out[prop] = defaultOptions[prop];
        if (editor) for (var prop in editor)
            if (editor[prop] !== undefined) out[prop] = editor[prop];
        if (options) for (var prop in options)
            if (options[prop] !== undefined) out[prop] = options[prop];
        if (out.hint.resolve) out.hint = out.hint.resolve(cm, pos)
        return out;
    }

    function getText(completion) {
        if (typeof completion == "string") return completion;
        else return completion.text;
    }

    function buildKeyMap(completion, handle) {
        var baseMap = {
            Up: function() {handle.moveFocus(-1);},
            Down: function() {handle.moveFocus(1);},
            PageUp: function() {handle.moveFocus(-handle.menuSize() + 1, true);},
            PageDown: function() {handle.moveFocus(handle.menuSize() - 1, true);},
            Home: function() {handle.setFocus(0);},
            End: function() {handle.setFocus(handle.length - 1);},
            Enter: handle.pick,
            Tab: handle.pick,
            Esc: handle.close
        };
        var custom = completion.options.customKeys;
        var ourMap = custom ? {} : baseMap;
        function addBinding(key, val) {
            var bound;
            if (typeof val != "string")
                bound = function(cm) { return val(cm, handle); };
            // This mechanism is deprecated
            else if (baseMap.hasOwnProperty(val))
                bound = baseMap[val];
            else
                bound = val;
            ourMap[key] = bound;
        }
        if (custom)
            for (var key in custom) if (custom.hasOwnProperty(key))
                addBinding(key, custom[key]);
        var extra = completion.options.extraKeys;
        if (extra)
            for (var key in extra) if (extra.hasOwnProperty(key))
                addBinding(key, extra[key]);
        return ourMap;
    }

    function getHintElement(hintsElement, el) {
        while (el && el != hintsElement) {
            if (el.nodeName.toUpperCase() === "LI" && el.parentNode == hintsElement) return el;
            el = el.parentNode;
        }
    }

    function Widget(completion, data) {
        this.completion = completion;
        this.data = data;
        this.picked = false;
        var widget = this, cm = completion.cm;

        var hints = this.hints = document.createElement("ul");
        var theme = completion.cm.options.theme;
        hints.className = "CodeMirror-hints " + theme;
        this.selectedHint = data.selectedHint || 0;

        var completions = data.list;
        for (var i = 0; i < completions.length; ++i) {
            var elt = hints.appendChild(document.createElement("li")), cur = completions[i];
            var className = HINT_ELEMENT_CLASS + (i != this.selectedHint ? "" : " " + ACTIVE_HINT_ELEMENT_CLASS);
            if (cur.className != null) className = cur.className + " " + className;
            elt.className = className;
            if (cur.render) cur.render(elt, data, cur);
            else elt.appendChild(document.createTextNode(cur.displayText || getText(cur)));
            elt.hintId = i;
        }

        var pos = cm.cursorCoords(completion.options.alignWithWord ? data.from : null);
        var left = pos.left, top = pos.bottom, below = true;
        hints.style.left = left + "px";
        hints.style.top = top + "px";
        // If we're at the edge of the screen, then we want the menu to appear on the left of the cursor.
        var winW = window.innerWidth || Math.max(document.body.offsetWidth, document.documentElement.offsetWidth);
        var winH = window.innerHeight || Math.max(document.body.offsetHeight, document.documentElement.offsetHeight);
        (completion.options.container || document.body).appendChild(hints);
        var box = hints.getBoundingClientRect(), overlapY = box.bottom - winH;
        var scrolls = hints.scrollHeight > hints.clientHeight + 1
        var startScroll = cm.getScrollInfo();

        if (overlapY > 0) {
            var height = box.bottom - box.top, curTop = pos.top - (pos.bottom - box.top);
            if (curTop - height > 0) { // Fits above cursor
                hints.style.top = (top = pos.top - height) + "px";
                below = false;
            } else if (height > winH) {
                hints.style.height = (winH - 5) + "px";
                hints.style.top = (top = pos.bottom - box.top) + "px";
                var cursor = cm.getCursor();
                if (data.from.ch != cursor.ch) {
                    pos = cm.cursorCoords(cursor);
                    hints.style.left = (left = pos.left) + "px";
                    box = hints.getBoundingClientRect();
                }
            }
        }
        var overlapX = box.right - winW;
        if (overlapX > 0) {
            if (box.right - box.left > winW) {
                hints.style.width = (winW - 5) + "px";
                overlapX -= (box.right - box.left) - winW;
            }
            hints.style.left = (left = pos.left - overlapX) + "px";
        }
        if (scrolls) for (var node = hints.firstChild; node; node = node.nextSibling)
            node.style.paddingRight = cm.display.nativeBarWidth + "px"

        cm.addKeyMap(this.keyMap = buildKeyMap(completion, {
            moveFocus: function(n, avoidWrap) { widget.changeActive(widget.selectedHint + n, avoidWrap); },
            setFocus: function(n) { widget.changeActive(n); },
            menuSize: function() { return widget.screenAmount(); },
            length: completions.length,
            close: function() { completion.close(); },
            pick: function() { widget.pick(); },
            data: data
        }));

        if (completion.options.closeOnUnfocus) {
            var closingOnBlur;
            cm.on("blur", this.onBlur = function() { closingOnBlur = setTimeout(function() { completion.close(); }, 100); });
            cm.on("focus", this.onFocus = function() { clearTimeout(closingOnBlur); });
        }

        cm.on("scroll", this.onScroll = function() {
            var curScroll = cm.getScrollInfo(), editor = cm.getWrapperElement().getBoundingClientRect();
            var newTop = top + startScroll.top - curScroll.top;
            var point = newTop - (window.pageYOffset || (document.documentElement || document.body).scrollTop);
            if (!below) point += hints.offsetHeight;
            if (point <= editor.top || point >= editor.bottom) return completion.close();
            hints.style.top = newTop + "px";
            hints.style.left = (left + startScroll.left - curScroll.left) + "px";
        });

        CodeMirror.on(hints, "dblclick", function(e) {
            var t = getHintElement(hints, e.target || e.srcElement);
            if (t && t.hintId != null) {widget.changeActive(t.hintId); widget.pick();}
        });

        CodeMirror.on(hints, "click", function(e) {
            var t = getHintElement(hints, e.target || e.srcElement);
            if (t && t.hintId != null) {
                widget.changeActive(t.hintId);
                if (completion.options.completeOnSingleClick) widget.pick();
            }
        });

        CodeMirror.on(hints, "mousedown", function() {
            setTimeout(function(){cm.focus();}, 20);
        });

        CodeMirror.signal(data, "select", completions[this.selectedHint], hints.childNodes[this.selectedHint]);
        return true;
    }

    Widget.prototype = {
        close: function() {
            if (this.completion.widget != this) return;
            this.completion.widget = null;
            this.hints.parentNode.removeChild(this.hints);
            this.completion.cm.removeKeyMap(this.keyMap);

            var cm = this.completion.cm;
            if (this.completion.options.closeOnUnfocus) {
                cm.off("blur", this.onBlur);
                cm.off("focus", this.onFocus);
            }
            cm.off("scroll", this.onScroll);
        },

        disable: function() {
            this.completion.cm.removeKeyMap(this.keyMap);
            var widget = this;
            this.keyMap = {Enter: function() { widget.picked = true; }};
            this.completion.cm.addKeyMap(this.keyMap);
        },

        pick: function() {
            this.completion.pick(this.data, this.selectedHint);
        },

        changeActive: function(i, avoidWrap) {
            if (i >= this.data.list.length)
                i = avoidWrap ? this.data.list.length - 1 : 0;
            else if (i < 0)
                i = avoidWrap ? 0  : this.data.list.length - 1;
            if (this.selectedHint == i) return;
            var node = this.hints.childNodes[this.selectedHint];
            if (node) node.className = node.className.replace(" " + ACTIVE_HINT_ELEMENT_CLASS, "");
            node = this.hints.childNodes[this.selectedHint = i];
            node.className += " " + ACTIVE_HINT_ELEMENT_CLASS;
            if (node.offsetTop < this.hints.scrollTop)
                this.hints.scrollTop = node.offsetTop - 3;
            else if (node.offsetTop + node.offsetHeight > this.hints.scrollTop + this.hints.clientHeight)
                this.hints.scrollTop = node.offsetTop + node.offsetHeight - this.hints.clientHeight + 3;
            CodeMirror.signal(this.data, "select", this.data.list[this.selectedHint], node);
        },

        screenAmount: function() {
            return Math.floor(this.hints.clientHeight / this.hints.firstChild.offsetHeight) || 1;
        }
    };

    function applicableHelpers(cm, helpers) {
        if (!cm.somethingSelected()) return helpers
        var result = []
        for (var i = 0; i < helpers.length; i++)
            if (helpers[i].supportsSelection) result.push(helpers[i])
        return result
    }

    function fetchHints(hint, cm, options, callback) {
        if (hint.async) {
            hint(cm, callback, options)
        } else {
            var result = hint(cm, options)
            if (result && result.then) result.then(callback)
            else callback(result)
        }
    }

    function resolveAutoHints(cm, pos) {
        var helpers = cm.getHelpers(pos, "hint"), words
        if (helpers.length) {
            var resolved = function(cm, callback, options) {
                var app = applicableHelpers(cm, helpers);
                function run(i) {
                    if (i == app.length) return callback(null)
                    fetchHints(app[i], cm, options, function(result) {
                        if (result && result.list.length > 0) callback(result)
                        else run(i + 1)
                    })
                }
                run(0)
            }
            resolved.async = true
            resolved.supportsSelection = true
            return resolved
        } else if (words = cm.getHelper(cm.getCursor(), "hintWords")) {
            return function(cm) { return CodeMirror.hint.fromList(cm, {words: words}) }
        } else if (CodeMirror.hint.anyword) {
            return function(cm, options) { return CodeMirror.hint.anyword(cm, options) }
        } else {
            return function() {}
        }
    }

    CodeMirror.registerHelper("hint", "auto", {
        resolve: resolveAutoHints
    });

    CodeMirror.registerHelper("hint", "fromList", function(cm, options) {
        var cur = cm.getCursor(), token = cm.getTokenAt(cur)
        var term, from = CodeMirror.Pos(cur.line, token.start), to = cur
        if (token.start < cur.ch && /\w/.test(token.string.charAt(cur.ch - token.start - 1))) {
            term = token.string.substr(0, cur.ch - token.start)
        } else {
            term = ""
            from = cur
        }
        var found = [];
        for (var i = 0; i < options.words.length; i++) {
            var word = options.words[i];
            if (word.slice(0, term.length) == term)
                found.push(word);
        }

        if (found.length) return {list: found, from: from, to: to};
    });

    CodeMirror.commands.autocomplete = CodeMirror.showHint;

    var defaultOptions = {
        hint: CodeMirror.hint.auto,
        completeSingle: true,
        alignWithWord: true,
        closeCharacters: /[\s()\[\]{};:>,]/,
        closeOnUnfocus: true,
        completeOnSingleClick: true,
        container: null,
        customKeys: null,
        extraKeys: null
    };

    CodeMirror.defineOption("hintOptions", null);
});